(a) Field of the Invention
The present invention relates to load modulation-based beamspace MIMO transmission method and apparatus.
(b) Description of the Related Art
Recently, with the progress of mobile smart devices and services, we are now moving into a hyper-connection society and the age of big data. As a result, mobile traffic doubling every year and is expected to be increased by 1000 times or more over the next 10 years. Due to the sudden increase in the mobile traffic, a burden of a mobile carrier is becoming more and more increased.
Generally, capacity of a wireless network is determined based on a spectrum bandwidth, frequency efficiency, and cell density. Recently, researches for using a millimeter wave to secure a new frequency band have been conducted, but the installation of a great number of small cells and the improvement in frequency efficiency are expected to be first realized. To facilitate the installation of small cells, a small base station is more urgently required. In frequency efficiency, there is a need to efficiently realize a multi-input multi-output (MIMO) technology. However, to realize the MIMO technology, a plurality of RF chains need to be installed in a base station and a terminal of as many as the number of antennas, and therefore it is difficult to implement the MIMO in economical costs and hardware. Further, a spatial constraint occurs due to the disposition of the plurality of antennas, and therefore the existing MIMO technology has a limitation in application to the small base station and the terminal.